Ion Production via Optical Field Ionization of Atoms and Ions: Results from Early Work

Optical field ionization of atoms, ions and molecules rapidly progresses sequentially through higher charge states. The time-dependent field of a single high intensity laser pulse can multiply ionize a multielectron atom during its risetime such that the peak intensity predictably 'sees' ions with the highest possible charge state (as determined by the peak intensity level). Common OFI models are reasonably predictive and closed form expressions for threshold and saturation laser intensities (in terms of relevant ionization potentials) bracket a useful range for ion production. They can also facilitate the design of ion sources and laser diagnostics. Results are given from the early OFI studies in gases and aluminum vapor conducted at the Lawrence Livermore National Laboratory